U.S. patent number 6,593,718 [Application Number 09/657,791] was granted by the patent office on 2003-07-15 for horizontal multi-joint industrial robot.
This patent grant is currently assigned to Tazmo Co., Ltd.. Invention is credited to Katsuhiro Yamazoe.
United States Patent |
6,593,718 |
Yamazoe |
July 15, 2003 |
Horizontal multi-joint industrial robot
Abstract
A horizontal multi-joint industrial robot has a construction in
which rotational driving force is transmitted from rotational
driving sources placed in a base through driving force transmitting
mechanism placed in arms and connecting parts to each of arms and a
robot hand. This construction in which rotational driving sources
for arms and robot hand are placed concentratively in the base,
eliminates the need for routing electric lines in moving parts,
thereby preventing rotational movements of the arms and robot hand
from decreasing the reliability, and besides allowing inertial
moments to reduce by decreasing weights of the moving parts.
Inventors: |
Yamazoe; Katsuhiro (Okayama,
JP) |
Assignee: |
Tazmo Co., Ltd. (Okayama,
JP)
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Family
ID: |
17545903 |
Appl.
No.: |
09/657,791 |
Filed: |
September 8, 2000 |
Foreign Application Priority Data
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Sep 28, 1999 [JP] |
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11-274738 |
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Current U.S.
Class: |
318/568.11 |
Current CPC
Class: |
B25J
9/042 (20130101); B25J 9/104 (20130101) |
Current International
Class: |
B25J
9/04 (20060101); B25J 9/02 (20060101); B25J
9/10 (20060101); B25J 009/18 (); G05B 019/19 () |
Field of
Search: |
;318/568.11-568.25
;414/730-744.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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8-274140 |
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Oct 1996 |
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JP |
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9-285982 |
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Nov 1997 |
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JP |
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Primary Examiner: Donels; Jeffrey
Attorney, Agent or Firm: Jordan and Hamburg LLP
Claims
What is claimed is:
1. A horizontal multi-joint industrial robot, comprising: a base;
arms sequentially pivotally attached to one another, a proximal end
portion of a lowest one of said arms being rotatably supported by
said base about a primary axis of rotation; a robot hand rotatably
supported by a distal end portion of a highest one of said arms,
said distal end portion being movable at least along a curved path
which passes through said primary axis; a rotational driving source
contained in said base including motors for rotatably driving said
arms and said robot hand, said motors including a robot hand
rotation motor; and a driving force transmitting mechanism for
transmitting rotational driving force from said rotational driving
source to the arms and the robot hand, respective portions of said
driving force transmitting mechanism being provided in each of the
arms and connecting parts of the arms, said driving force
transmitting mechanism being operable to impart rotation to said
robot hand by transmission of driving force from said robot hand
rotation motor independent of rotational motion transmitted to the
arms by said driving force transmitting mechanism.
2. The horizontal multi-joint industrial robot as claimed in claim
1, wherein said driving force transmitting mechanism includes a
rotational mechanism for rotating said robot hand around a
connecting part of the distal end portion of the highest arm.
3. The horizontal multi-joint industrial robot as claimed in claim
1, wherein said driving force transmitting mechanism includes a
mechanism for supporting said robot hand so as to move in a seesaw
manner in the distal end portion of the highest arm, and giving
tilting motions to said robot hand.
4. The horizontal multi-joint industrial robot as claimed in claim
1, wherein said driving force transmitting mechanism includes a
mechanism for supporting said robot hand so as to enable said robot
hand to rotationally move around a horizontal axis in the distal
end portion of the highest arm, and for imparting rotational
movement around the horizontal axis to said robot hand.
5. The horizontal multi-joint industrial robot as claimed in claim
1, wherein: said arms are sequentially attached from the base in
order of first, second and third arms; said motors further include
an arm rotation motor for rotating said first and third arms and an
arm extension motor for rotating said second arm; and said driving
force transmitting mechanism being further operable to impart
rotation to said first and third arms by independent transmission
of driving force from said arm rotation motor, and to impart
rotation to said second arm by independent transmission of driving
force from said arm extension motor.
6. The horizontal multi-joint industrial robot as claimed in claim
2, wherein: said arms are sequentially attached from the base in
order of first, second and third arms; said motors further include
an arm rotation motor for rotating said first and third arms and an
arm extension motor for rotating said second arm; and said driving
force transmitting mechanism being further operable to impart
rotation to said first and third arms by independent transmission
of driving force from said arm rotation motor, and to impart
rotation to said second arm by independent transmission of driving
force from said arm extension motor.
7. The horizontal multi-joint industrial robot as claimed in claim
3, wherein: said arms are sequentially attached from the base- in
order of first, second and third arms; said motors further include
an arm rotation motor for rotating said first and third arms and an
arm extension motor for rotating said second arm; and said driving
force transmitting mechanism being further operable to impart
rotation to said first and third arms by independent transmission
of driving force from said arm rotation motor, and to impart
rotation to said second arm by independent transmission of driving
force from said arm extension motor.
8. The horizontal multi-joint industrial robot as claimed in claim
4, wherein: said arms are sequentially attached from the base in
order of first, second and third arms; said motors further include
an arm rotation motor for rotating said first and third arms and an
arm extension motor for rotating said second arm; and said driving
force transmitting mechanism being further operable to impart
rotation to said first and third arms by independent transmission
of driving force from said arm rotation motor, and to impart
rotation to said second arm by independent transmission of driving
force from said arm extension motor.
9. The horizontal multi-joint industrial robot as claimed in claim
5, wherein said driving force transmitting mechanism further
comprises axes passing through each of the connecting parts of said
arms, pulleys that are fixed on said axes, and belts that are
looped between pulleys of proximal end portions and distal end
portions of the arms.
10. The horizontal multi-joint industrial robot as claimed in claim
6, wherein said driving force transmitting mechanism further
comprises axes passing through each of the connecting parts of said
arms, pulleys that are fixed on said axes, and belts that are
looped between pulleys of proximal end portions and distal end
portions of the arms.
11. The horizontal multi-joint industrial robot as claimed in claim
7, wherein said driving force transmitting mechanism further
comprises axes passing through each of the connecting parts of said
arms, pulleys that are fixed on said axes, and belts that are
looped between pulleys of proximal end portions and distal end
portions of the arms.
12. The horizontal multi-joint industrial robot as claimed in claim
8, wherein said driving force transmitting mechanism further
comprises axes passing through each of the connecting parts of said
arms, pulleys that are fixed on said axes, and belts that are
looped between pulleys of proximal end portions and distal end
portions of the arms.
13. A horizontal multi-joint industrial robot, comprising: a base;
a first arm, a second arm and a third arm which are sequentially
pivotally attached, a proximal end portion of the first arm and a
robot hand are pivotally supported in the base and a distal end
portion of the third arm, respectively; an arm rotation motor for
driving said first and third arms to rotate, an arm extension motor
for driving the second arm to rotate, and a robot hand rotation
motor for driving the robot hand to rotate, each of said motors
being contained in the base; an arm rotation driving force
transmitting mechanism for independently transmitting rotational
driving force from said arm rotation motor to said first and third
arms, an arm extension driving force transmitting mechanism for
independently transmitting rotational driving force from said arm
extension motor to said second arm, and a robot hand rotation
driving force transmitting mechanism for independently transmitting
rotation driving force from said robot hand rotation motor to said
robot hand, respective portions of each of said arm rotation
driving force transmitting mechanism, said arm extension driving
force transmitting mechanism and said robot hand rotation driving
force transmitting mechanism being equipped in each of the arms and
connecting parts of the arms; said arm rotation driving force
transmitting mechanism including a first pulley which is fixed on
an output axis of said arm rotation motor, a second pulley which is
fixed on the proximal end portion of said first arm, a first belt
which is looped between said first and second pulleys, a third
pulley which is fixed on the distal end portion of said first arm,
and fixed on an upper part of a stationary axis being toward an
inside of the second arm through a connecting part between the
first and second arms, a fourth pulley fixed on the proximal end
portion of said third arm, and a second belt that is looped between
said third and fourth pulleys; said arm extension driving force
transmitting mechanism including a fifth pulley that is fixed on an
output axis of said arm extension motor, sixth and seventh pulleys
that are fixed respectively on upper and lower ends of a rotational
axis passing through a proximal end portion of said first arm and
being rotatably fixed in said proximal end portion of said first
arm, an eighth pulley that is fixed on a proximal end portion of
said second arm, a third belt that is looped between said fifth and
seventh pulleys, and a fourth belt that is looped between said
sixth and eighth pulleys; and said robot hand rotation driving
force transmitting mechanism including a ninth pulley that is fixed
on an output axis of said robot hand rotation motor, tenth and
eleventh pulleys that are respectively fixed on upper and lower
ends of a drum passing through the proximal end portion of said
first arm and being rotatably supported by said proximal end
portion, said third pulley and a twelfth pulley that are fixed on
upper and lower ends of a drum rotatably supported by said
stationary axis, thirteenth and fourteenth pulleys that are fixed
on upper and lower ends of a rotational axis rotatably supported by
the proximal end portion of said third arm, a fifteenth pulley that
is fixed on a lower end of a rotational axis rotatably supported by
a distal end portion of said third arm, said robot hand that is
fixed on an upper end of the rotational axis, a fifth belt that is
looped between said ninth and eleventh pulleys, a sixth belt that
is looped between said tenth and twelfth pulleys, a seventh belt
that is looped between said fourteenth pulley and a sixteenth
pulley, and an eight belt that is looped between said thirteenth
and fifteenth pulleys.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to a horizontal multi-joint robot
that is employed for conveying a wafer in a semi-conductor
producing factory, and especially relates to an art for placing
rotational driving sources concentratively in one place, thereby
avoiding routing energy supplying means to the rotational driving
sources, such as electric wires for power supply, and arrangements
of oil hydraulic or pneumatic pipes, and to an art for reducing
weights of moving parts.
Concerning a conventional horizontal multi-joint robot known as a
scholar type, as shown in FIG. 5, a robot 100 has a construction
wherein connecting parts 101 and 102 corresponding to joints of
arms 103 and 104 with multi degrees of freedom, are equipped with
arm rotational driving sources 105 and 106 that respectively drive
the arms 103 and 104, and the arm 104 is equipped in its distal end
with a robot hand rotational driving source 107 in addition to
driving sources 105 and 106.
However, in the above-mentioned construction, it is needed to
supply energy to the connecting parts between arms 103 and 104, and
to distal end of the arm 104, for activating the arm rotational
driving sources 105 and 106, and robot hand rotational driving
source 107. For example, if each of the driving sources is a motor,
it is necessary to connect an electric wire to each of the driving
sources and if each of the driving sources is an oil hydraulic or
air pressure motor, it is necessary to place the pipe arrangements
for supplying pressed oil or air. Rotational movements of the arms
and robot hand gives mechanical load to these electric wires and
pipe arrangements, thereby reducing its own reliability. Further,
placing the rotational driving sources in each of the arms
increases weights of the moving parts, thereby increasing inertial
moments of the moving parts, and decreasing transportable weights
thereof.
SUMMARY OF THE INVENTION
This invention is made to solve the above-mentioned problems. One
object of the present invention is to provide a horizontal
multi-joint robot wherein rotational driving sources for arms and a
robot hand are placed concentratively in a base member in order to
eliminate the need for routing energy-supplying electric wires and
pipe arrangements, thereby preventing rotational movements of the
arms and robot hand from decreasing the reliability, and wherein
inertial moments can be reduced by decreasing weights of moving
parts.
In order to achieve the above-mentioned object, according to one
aspect of the present invention, there is provided a horizontal
multi-joint industrial robot in which plural arms are sequentially
pivotally attached, a proximal end portion of the lowest arm is
rotatably supported by a base, and a robot hand is rotatably
supported by a distal end portion of the highest arm: wherein a
rotational driving source for driving said arms and robot hand to
rotate is contained in said base; and wherein a driving force
transmitting mechanism for transmitting rotational driving force
from said rotational driving source to each of the arms and robot
hand is provided in each of the arms and connecting parts of the
arms.
In the above-described composition, not limited to an electric
motor, an oil hydraulic motor or a pneumatic motor can be employed
as said rotational driving source. Besides, one driving source for
arm rotation can drive at least two arms to rotate. Further, it is
possible to locate the arm rotational driving source and robot hand
rotational driving source separately.
Further, in the above described-composition, the rotational driving
source which is contained in the base member rotates plural arms
and a robot hand through the driving force transmitting mechanism
which is provided in each of the arms and connecting parts. This
composition eliminates the need for routing energy-supplying
electric wires and pipe arrangements, and prevents a break or a
damage of the wire caused by an increase of mechanical load due to
the rotation of the arms and robot hand. Further, this composition
makes it possible to reduce weights of the arms, which decreases
inertial moments, thereby allowing transportable weights to be
increased, and motion speed of the robot to become faster.
In the above-mentioned horizontal multi-joint industrial robot,
said driving force transmitting mechanism includes a rotational
mechanism for rotating said robot hand around the connecting part
of the distal end portion of the highest arm.
Further, in the above-mentioned horizontal multi-joint industrial
robot, said driving force transmitting mechanism includes a
mechanism for supporting said robot hand so as to move in a seesaw
manner in the distal end portion of the highest arm, and giving
tilting motions to said robot hand. This composition allows the
robot hand to move in an up-and-down direction, thereby enhancing
workability.
Further, in the above-mentioned horizontal multi-joint industrial
robot, said driving force transmitting mechanism includes a
mechanism for supporting said robot hand so as to rotationally move
around a horizontal axis in the distal end portion of the highest
arm, and giving rotational movements around the horizontal axis to
said robot hand. This composition allows the robot hand to rotate
around the horizontal axis, thereby enhancing workability.
Furthermore, in the above-mentioned horizontal multi-joint
industrial robot, said arms are sequentially attached from the base
in order of first, second and third arms; wherein said rotational
driving source comprises: an arm rotation motor for rotating said
first and third arms; an arm extension motor for rotating said
second arm; and a robot hand rotation motor for rotating said robot
hand; and wherein said driving force transmitting mechanism
includes a mechanism that said arm rotation motor drives first and
third arms to rotate, and said arm extension motor drives said
second arm to rotate. This composition allows one driving source
for arm rotation to drive at least two arms to rotate, thereby
making it possible to decrease the number of rotational driving
sources.
Furthermore, in the horizontal multi-joint industrial robot,
wherein said driving force transmitting mechanism comprises axes
passing through each of the connecting parts of said arms, pulleys
that are fixed on said axes, and belts that are looped between
pulleys of proximal end portions and distal end portions of the
arms. The composition that the pulleys and belts are employed in
the driving force transmitting mechanism, suppresses noise and dust
raising under operating conditions. Therefore, this is suitable for
use in a semi-conductor factory.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an external view of a horizontal multi-joint robot
according to one embodiment of the present invention.
FIG. 2 is a side-sectional view of a robot according to a first
embodiment of the present invention.
FIG. 3 is a side-sectional view of a robot according to a second
embodiment of the present invention.
FIG. 4 is a side-sectional view of a robot according to a third
embodiment of the present invention.
FIG. 5 is a perspective view of a conventional horizontal
multi-joint industrial robot.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE PRESENT
INVENTION
Now, referring to the drawings, a horizontal multi-joint industrial
robot equipped with three degrees of freedom according to one
embodiment of the present invention will be explained. FIG. 1 is an
external view of a robot according to the first embodiment of the
present invention, and FIG. 2 is a side sectional view of said
robot. The robot includes a base 1, and includes a first arm 2, a
second arm 3 and a third arm 4 that are sequentially pivotally
attached, and mounted to said base 1. The first arm 2 has a
proximal end portion that is rotatably mounted on the base 1, and a
robot hand 5 for holding a wafer W is rotatably mounted on a distal
end portion of the third arm 4. The base 1 contains an arm rotation
motor 8 that drives the first and third arms 2 and 4 to rotate, an
arm extension motor 6 that drives the second arm 3 to rotate, and a
robot hand rotation motor 7 that drives the robot hand 5 to
rotate.
The arm rotation motor 8 rotates the first and third arms 2 and 4
through a driving force transmitting mechanism for arm rotation.
The arm extension motor 6 rotates the second arm 3 through a
driving force transmitting mechanism for arm extension. The robot
hand rotation motor 7 rotates the robot hand 5 through a driving
force transmitting mechanism for robot hand rotation.
The driving force transmitting mechanism for arm rotation comprises
a pulley 32, a pulley 34, a belt 33, a pulley 36, a pulley 38, and
a belt 37. The pulley 32 is fixed on an output axis of the arm
rotation motor 8. The pulley 34 is fixed on the proximal end
portion of the first arm 2. The belt 33 is looped between said
pulleys 32 and 34. The pulley 36 is fixed on a distal end portion
of the first arm 2, and fixed on an upper section of a stationary
axis 35 that is toward an inside of the second arm 3 through a
connecting part between the first and second arms 2 and 3. The
pulley 38 is fixed on a proximal end portion of the third arm 4.
The belt 37 is looped between the pulleys 36 and 38.
The driving force transmitting mechanism for arm extension
comprises pulleys 9, 13, 11 and 15, and belts 10 and 14. The pulley
9 is fixed on the output axis of the arm extension motor 6. The
pulleys 13 and 11, which pass through the proximal end portion of
the first arm 1, are respectively fixed on upper and lower ends of
a rotational axis 12 that is rotatably supported by said proximal
end portion. The pulley 15 is fixed on the proximal end portion of
the second arm 3. The belt 10 is looped between the pulleys 9 and
11, and the belt 14 is looped between the pulleys 13 and 15.
The driving force transmitting mechanism for robot hand rotation
comprises pulleys 16, 20, 18, 36, 22, 28, 26 and 30, a robot hand
5, and belts 17, 21, 25 and 29. The pulley 16 is fixed on the
output axis of the robot hand rotation motor 7. The pulleys 20 and
18, which pass through the proximal end portion of the first arm 2,
are respectively fixed on upper and lower ends of a drum 19 that is
rotatably supported by said proximal end portion. The pulleys 36
and 22 are respectively fixed on upper and lower ends of a drum 23
that is rotatably supported by the stationary axis 35. The pulleys
28 and 26 are respectively fixed on upper and lower ends of a
rotational axis 27 that is rotatably supported by the proximal end
portion of the third arm 4. The pulley 30 is fixed on a lower end
of a rotational axis 31 that is rotationaly supported by an end of
the third arm 4. The robot hand 5 is fixed on an upper end of a
rotational axis 31. The belt 17 is looped between the pulleys 16
and 18, the belt 21 between the pulleys 20 and 22, the belt 25
between the pulleys 24 and 26, and the belt 29 between the pulleys
28 and 30.
The explanation is nextly given to actions of the above-described
composition. The rotational driving force from the arm rotation
motor 8 in the base 1 is transmitted to the first arm 2 that is
fixed to the pulley 34 connected with the pulley 32 fixed on the
output axis of the arm rotation motor 8 through the belt 33,
thereby rotating the first arm 2. Then, said driving force is
transmitted to the third arm 4 that is fixed to the pulley 38
diameter of which has a ratio of 1:1 to that of the pulley 36,
through the stationary axis 35 that is fixed to the first arm 2,
the pulley 36 that is fixed on said axis 35, and the belt 37,
thereby rotating the third arm 4. Accordingly, the third arm 4 is
connected to the first arm 2 at a ratio of 1:1, so that the third
and first arms 4 and 2 always rotate in a same direction.
The rotational driving force from the arm extension motor 6 in the
base 1 is transmitted to the pulleys 11 and 13 that are fixed on
the rotational axis 12, through the pulley 9 fixed on the output
axis of said motor 6 and through the belt 10, and then transmitted
to the second arm 3 fixed to the pulley 15, through the pulley 13
and the belt 14, thereby rotating the second arm 3.
The rotational driving force from the robot hand rotation motor 7
in the base 1 is transmitted to the pulleys 18 and 20 that are
fixed on the rotational drum 19, through the pulley 16 fixed on the
output axis of said motor 7 and through belt 17. The pulley 20
transmits the driving force through the belt 21 to the pulleys 22
and 24 that are fixed on the rotational drum 23. The pulley 24
transmits the driving force through belt 25 to the pulleys 26 and
28 that are fixed on the rotational axis 27, and the pulley 28
transmits the driving force through the belt 29 to the rotational
axis 31 fixed on the pulley 30, and to the robot hand 5 fixed on
said axis 31, thereby rotating the robot hand 5.
As described above, the first and third arms 2 and 4 are rotated by
the rotational driving force from the arm rotation motor 8, the
second arm 3 is rotated by the rotational driving force from the
arm extension motor 6, and the robot hand 5 is rotated by the
rotational driving force from the robot hand rotational motor 7.
Thus, every rotational driving source is mounted in a stationary
part of the base 1. Consequently, the rotational driving force can
be transmitted to each of arms without routing electric lines for
supplying electric power through the arms as moving parts.
FIG. 3 is a side-sectional view of a robot according to the second
embodiment of the present invention. The second embodiment makes it
possible to tilt the robot hand. The robot has an arm structure
wherein three arms of the first, second and third arms 2, 3 and 41
are sequentially attached from the base 1 that includes a
rotational driving source in a stationary part, and a robot hand
for holding a wafer W is connected in a distal end portion of the
third arm 41. The rotational driving force from the arm rotation
motor 8 in the base 1 is transmitted through the pulley 32 fixed on
the output axis of said motor 8 and through the belt 33, to the
first arm 2 that is fixed to the pulley 34, thereby rotating the
first arm 2. Then, said driving force is transmitted through the
stationary axis 35 fixed to the first arm 2, the pulley 43 fixed on
said axis 35, and the belt 37, to the third arm 41 that is fixed to
the pulley 38 diameter of which has a ratio of 1:2 to that of the
pulley 43, thereby rotating the third arm 41. Since the third arm
41 is connected to the first arm 2 at a ratio of 1:2, the
rotational amount of the third arm 41 always maintains half of the
angle that is formed between the first and second arms 2 and 3.
The rotational driving force from the arm extension motor 6 in the
base 1 is transmitted through the pulley 9 fixed on the output axis
of said motor 6 and through the belt 10, to the pulleys 11 and 13
that are fixed on the rotational axis 12. Said driving force is
transmitted through the pulley 13 and belt 14, to the second arm 3
that is fixed to the pulley 15, thereby rotating the second arm
3.
The rotational driving force from the robot hand rotation motor 7
in the base 1 is transmitted through the pulley 16 fixed on the
output axis of said motor 7 and through the belt 17, to the pulleys
18 and 20 that are fixed on the rotational drum 19. The pulley 20
transmits the driving force through the belt 21 to the pulleys 22
and 24 that are fixed on the rotational drum 23. The pulley 24
transmits the driving force through the belt 25 to the pulley 26
and a cam 39 that are fixed on the rotational axis 27. The cam 39
has a construction, which can convert rotational motions into
up-and-down motions, transmits the driving force to the robot hand
5 that is sandwiched between the cam 39 fixed on the axis 40, and a
spring 42. The rotation of the cam 39 provides tilt motions to the
robot hand 5 in an up-and-down direction shown by a center line L
through the axis 40.
The first and second arms 2 and 3 are approximately equal in
length. In order to provide the robot hand 5 with linear motions
and rotational motions about a connecting part between the base 1
and the first arm 2, a controller (not shown in the figures)
controls the arm extension motor 6 and arm rotation motor 8. The
robot hand 5 is given the up-and-down motions by controlling the
robot hand rotation motor 7.
FIG. 4 is a side sectional view showing a robot according to the
third embodiment of the present invention. This embodiment makes it
possible to rotate the robot hand around an axis of a horizontal
direction. The robot has an arm structure in which three arms of
the first, second and third arms 2, 3 and 46 are sequentially
attached from the base 1 that includes a rotational driving source
in a stationary part, and the robot hand 5 for holding a wafer W is
connected in a distal end portion of the third arm 46. The
rotational driving force from the arm rotation motor 8 in the base
1 is transmitted through the pulley 32 fixed on the output axis of
said motor 8 and through the belt 33, to the first arm 2 that is
fixed to the pulley 34, thereby rotating the first arm 2. Then,
said driving force is transmitted through the stationary axis 35
fixed to the first arm 2, the pulley 43 fixed on said axis 35, and
the belt 37, to the third arm 46 that is fixed to the pulley 38
diameter of which has a ratio of 1:2 to that of the pulley 43,
thereby rotating the third arm 46. Since the third arm 46 is
connected to the first arm 2 at a ratio of 1:2, the rotational
amount of the third arm 46 always maintains half of the angle that
is formed between the first and second arms 2 and 3.
The rotational driving force from the arm extension motor 6 in the
base 1 is transmitted through the pulley 9 fixed on the output axis
of said motor 6 and through the belt 10, to the pulleys 11 and 13
that are fixed on the stationary axis 12. Said driving force is
transmitted through the pulley 13 and belt 14 to the second arm 3
that is fixed to the pulley 15, thereby rotating the second arm
3.
The rotational driving force from the robot hand rotation motor 7
in the base 1 is transmitted through the pulley 16 fixed on the
output axis of said motor 7 and through the belt 17, to the pulleys
18 and 20 that are fixed on the rotational drum 19. The pulley 20
transmits the driving force through the belt 21 to the pulleys 22
and 24 that are fixed on the rotational drum 23. The pulley 24
transmits the driving force through the belt 25 to the pulley 26
and a bevel gear 44 that are fixed on the rotational axis 27,
thereby rotating the gear 44. The bevel gears 44 and 45 intersect
each other in an orthogonal angle direction. The robot hand 5 fixed
on the bevel gear 45 makes rotational motions on the center line L
around an axis of a horizontal direction.
The first and second arms 2 and 3 are approximately equal in
length. In order to provide the robot hand 5 with linear motions
and rotational motions about a connecting part between the base 1
and the first arm 2, a controller (not shown in the figures)
controls the arm extension motor 6 and arm rotation motor 8. The
robot hand 5 is given the rotational motions by controlling the
robot hand rotation motor 7.
In the above-described embodiments, the belts and pulleys are
employed as the driving force transmitting mechanisms. In case that
dust is raised by the belts and pulleys sliding, cleanliness in
movement space of the robot can be heightened by exhausting air
from the base under suction, which makes proper circumstances for
producing semi-conductors.
Having described preferred embodiments of the invention with
reference to the accompanying drawings, it is to be understood that
the invention is not limited to those precise embodiments, and that
various changes and modifications may be effected therein by one
skilled in the art without departing from the scope or spirit of
the invention as defined in the appended claims. For example, not
limited to the pulley 43 that is fixed on the stationary axis 35,
and diameter of which is half of that of the pulley 38 as employed
in the second and third embodiments, the pulley diameter of which
is same as that of the pulley 38, can also be employed according to
work environments.
* * * * *